Legend:

And then we update them [https://core.trac.wordpress.org/browser/trunk/wp-admin/includes/post.php#L205 all at once] and add all on every revision and autosave? That would make the postmeta table "explode" :)

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And then we update them [/browser/trunk/wp-admin/includes/post.php#L205 all at once] and add all on every revision and autosave? That would make the postmeta table "explode" :)

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Why not one meta field that keeps all needed data? What happens when more than one format meta is set on a post? Do we need to keep all unused meta for the main post in addition to having it in the revisions?